This is what I wrote to them:
"The flight from Vienna to Brussels were delayed more than 40 minutes which led to the missing of connection from Brussels to Billund.

1. I had to take 2 other flights to get to my destination.
2. I had my medicine in my luggage which I could not take because the airline did not deliver it to me (although I insisted to have my medicine)
3. Instead of reaching Billund at 11:05, I arrived there at 18:30.

This is extremely irresponsible and I would like an official apology plus reimbursement of the ticket price plus reimbursement for the long hours I had to wait in the airport with no service plus the food and drinks I had to buy at the airport.

This was my second experience with Austrian and both were traumatic. In July 20th 2016, my family and I were travelling for attending a wedding ceremony with 6VANNV flight from Copenhagen to Vienna and Vienna to Tehran. Austrian lost our luggages with all that was needed for our ceremony and delivered them after 2 days.

I am extremely disappointed, I had a difficult time in Brussels Airport, my family were waiting for me, and had to wait 7.5 more hours. All of these should be accounted for and they should never happen to anyone."

They simply replied that they are not going to do anything about it!!!
Only give me a voucher for food for 30 Euros. I am paid 35 Euros per hour. Only the 7.5 hours of delay, they should compensate me for more than 180 Euros.

Apparently these people has no clue about providing service. They are just there to collect the money from you and do whatever they want.